The present invention relates to torque converters, and specifically to coreless torque converters having no cores.
Japanese Utility Model Provisional Publication No. 1-128055 shows a conventional coreless torque converter of a three-element, single-stage, two-phase type. In the impeller member of an ordinary torque converter having cores, the fluid flow is confined between a shell (outside wall of the torus section) and a core (inside wall of the torus section). In the coreless torque converter, the fluid flows within a central core region, and participates in power transmission. Therefore, the amount of the circulating flow is greater, and the capacity is improved. In the conventional coreless torque converter, however, the impeller blades are shaped so that the exit angle is substantially constant from the outer end to the inner end of the exit. Similar coreless torque converters are shown in Japanese Patent Provisional Publications Nos. 52-156269, 53-1757, and 52-147269, and SAE paper 861213, page 6.